Which of the following capacity is considered as a design capacity?
- ABasic capacity
- BPossible capacity
- CPractical capacityCorrect
- DAll of these
Solution
Concept
Practical Capacity
Formula
No standard formula exists; it is a conceptual design standard based on traffic conditions and level of service.
Step-by-step solution
Identify practical capacity as the maximum traffic flow attainable under prevailing roadway and traffic conditions without causing excessive delay, which makes it the standard used for design capacity.
Explanation
Practical capacity is considered the design capacity because it represents the maximum number of vehicles that can safely pass a point on a road without causing unreasonable delays or congestion under realistic traffic conditions.
Shortcut
Remember "Practical = Planned": Practical capacity is the real-world, practical traffic volume used for designing roads safely.
Common mistake
Many students confuse basic capacity with design capacity, assuming maximum ideal conditions are used for design, or incorrectly select "All of these."
Correct answer: C) Practical capacity